html {
    font-size: 50px;
}

@media (min-width: 768px) {
    html {
        font-size: 16px;
    }
}

html {
    position: relative;
    min-height: 100%;
}

header {
    min-height: 150px;
}

#main {
    min-height: 700px;
}
nav {
height:150px;
}
footer {
    min-height: 150px;
}

.col {
    min-height: 150px;
    min-width: 150px;
}
button {
    height: 100%;
}
